Back to EveryPatent.com
| United States Patent |
5,690,950
|
|
Beadle
, et al.
|
November 25, 1997
|
Insecticidal aliphatic carboxylic acid compositons
Abstract
A composition and method for killing insect larvae, in particular, fly
larvae, in poultry houses, manure piles, or other sites of habitation are
disclosed. The composition consists of one or more C.sub.2 to C.sub.6
aliphatic carboxylic acids or alkali metal, alkaline earth, ammonia,
primary, secondary, tertiary, or quaternary ammonium salts in an
acceptable formulation for larvacides. The formulation may be applied dry,
as an aerosol, or in aqueous or organic solvents.
| Inventors:
|
Beadle; James R. (San Diego, CA);
Zehner; Lee R. (Brookeville, MD);
Levin; Gilbert V. (Annapolis, MD);
Saunders; James P. (Rockville, MD);
Bozsa; Robert C. (Silver Spring, MD)
|
| Assignee:
|
Biospherics, Inc. (Beltsville, MD)
|
| Appl. No.:
|
725982 |
| Filed:
|
October 4, 1996 |
| Current U.S. Class: |
424/405; 514/919 |
| Intern'l Class: |
A01N 033/12; A01N 037/02; A01N 037/06; A01N 025/06; A01N 025/12 |
| Field of Search: |
424/405
514/919,557
|
References Cited
U.S. Patent Documents
| 2627487 | Feb., 1953 | Drake et al. | 514/919.
|
| 4166107 | Aug., 1979 | Miller et al. | 424/405.
|
| 4983390 | Jan., 1991 | Levy | 424/404.
|
| 5182096 | Jan., 1993 | Portas et al. | 424/405.
|
| 5399344 | Mar., 1995 | Yang et al. | 424/84.
|
| 5407656 | Apr., 1995 | Roozdar | 252/187.
|
| 5556881 | Sep., 1996 | Grahn Marisi | 514/557.
|
Other References
Dialog report including Sep. 3, 1993 Phoenix Gaxette article.
Press Advisory, U.S. Environmental Protection Agency, Sep. 16, 1994.
Reregistration Eligibility Document for Citric Acid, Case 4024, U.S. EPA,
Jun. 1992.
Anonymous, "Citric Acid Finds Niche in Food Treatment," Chemical Marketing
Reporter, Jun. 28, 1993.
James Giese, Anti-microbials: Assuring food safety, Food Technology, p.
102, Jun. 1994.
Anderson, M. E. and Marshall, R.T. "Reducing Microbial Populations..
Journal of Food Science", vol. 55, p. 903, 1990.
Doores,S. Organic Acids, in Antimicrobials in Food, Es. Davidson and
Branen, Barcel Dekker, N.Y. 1993, pp. 95-135.
Anonymous, Food Acidulants have many functions.. Food Engineering, Mar.
1979, p. 156.
|
Primary Examiner: Page; Thurman K.
Assistant Examiner: Sikha; Murthy
Attorney, Agent or Firm: Ramsey; William S.
Parent Case Text
This application is a continuation of application Ser. No. 08/328,875,
filed Oct. 25, 1994, now abandoned.
Claims
We claim:
1. A method for killing insect larvae comprising the step:
applying a larvacidal amount of one or more C.sub.2 to C.sub.6 aliphatic
carboxylic acids excluding acetic acid to the site of habitation of said
insect larvae.
2. The method of claim 1 wherein the insect is a member of the class
Insecta.
3. The method of claim 1 wherein the insect is a member of the order
Diptera.
4. The method of claim 1 wherein the insect is a member of the family
Muscidae.
5. The method of claim 1 wherein the insect is a housefly, face fly, or
stable fly.
6. The method of claim 1 wherein the insect is a housefly.
7. The method of claim 1 wherein the C.sub.2 to C.sub.6 aliphatic
carboxylic acid is citric acid, lactic acid, propionic acid, maleic acid,
tartaric acid, gluconic acid, fumaric acid, adipic acid, sorbic acid,
malonic acid, or malic acid.
8. The method of claim 1 wherein the C.sub.2 to C.sub.6 aliphatic
carboxylic acid is citric acid.
9. The method of claim 1 wherein the amount of one or more C.sub.2 to
C.sub.6 aliphatic carboxylic acids excluding acetic acid applied is from
0.4% to 40% by weight to weight of site of habitation material.
10. The method of claim 1 wherein the one or more C.sub.2 to C.sub.6
aliphatic carboxylic acids excluding acetic acid are applied dry as a
dust, granule, or aerosol, as an aqueous solution, or as a solution in
organic solvents.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to methods and chemical compositions for the
destruction of insect larvae.
2. Description of Related Art
Control of houseflies and other insects in commercial, industrial, and
residential settings has become difficult because of the development of
resistance to the traditional chemicals used. Existing methods of control
of houseflies around livestock dwellings are based on synthetic chemicals,
bait and light traps, and cultural techniques such as removal of animal
manure and general sanitation. There is a strong need for new methods of
control based on a different, safe for humans and animals, mode of action.
Citric acid and potassium sorbate, among other compounds, have been
proposed by the Environmental Protection Agency for exemption from the
pesticide regulations when these substances are sold, distributed, or used
as pesticides. (Press Advisory, U.S. Environmental Protection Agency, Sep.
16, 1994).
Citric acid is registered with the Environmental Protection Agency as a
disinfectant, sanitizer, fungicide, and scale remover. (Reregistration
Eligibility Document for Citric Acid, Case 4024, U.S. Environmental
Protection Agency, June 1992).
Citric acid, acetic acid, and lactic acid have been found to be effective
as anti-microbial agents when used to treat animal carcasses and seafood.
Coliform and aerobic microorganisms were reduced when citric acid was
applied to beef carcasses. It was speculated that the reductions in
bacterial counts were caused by the stress introduced into the environment
by the acids. Bacterial growth was inhibited when the acids were applied
immediately after carcass dehiding and pre-washing. (Anonymous, "Citric
Acid Finds Niche in Food Treatment", Chemical Marketing Reporter, Jun. 28,
1993).
The effectiveness of carboxylic acids as anti-microbial agents is known to
be a function of the pH of the food in which the agents are used. As food
pH increased from 1 to 7, the concentration of the active anti-microbial
form, the undissociated acid, decreased 2 orders of magnitude. For
example, 0.6, 0.15, and 0.7% of sorbic, benzoic, and propionic acids
respectively exist as the undissociated form at pH 7. Consequently, these
acids are not effective anti-microbials at this pH. (James Giese,
"Anti-microbials: Assuring Food Safety", Food Technology, p. 102, June
1994). Most bacteria in food grow best at a neutral pH (6.7 to 7.5). The
organic acids act as anti-microbials by lowering pH and thus retarding
bacterial growth (Anderson, M. E. and Marshall, R. T. "Reducing Microbial
Populations of Beef Tissues: Concentration and Temperature of an Acid
Mixture", Journal of Food Science, vol. 55, p. 903, 1990; and Doores, S.,
"Organic Acids", in Antimicrobials in Food, Eds.Davidson, P. M. and
Branen, A. L., (Marcel Dekker, Inc., N.Y 1993), pp. 95-135.)
The use of the carboxylic acids and salts of this invention as insecticides
has not been previously disclosed.
In contrast to the situation in foods, typical fly larvae environments, for
example chicken manure, have alkaline pH values between 7 and 9. These
values are too high to permit the organic acids to function as
anti-microbials. In addition, the salts of the organic acids are effective
as larvacides. This suggests the observed larvacidal activity and the
pH-derived anti-microbial activity of these compounds are not related in
any obvious way.
The organic acids of this invention have been proven safe for humans and
domestic animals at larvacidal levels, and, in fact, are generally
recognized as safe as food additives. These insecticides are completely
biodegraded to CO.sub.2 and water and therefore are environmentally
benign. The larvacides of this invention interfere with the insect life
cycle at the larval stage, thus interrupting the life cycle prior to the
insect's emergence as a pest. These larvacides are stable when stored dry
or in solution and are economical when used as recommended.
SUMMARY OF THE INVENTION
This invention provides a method and formulations for preventing insect
infestations, especially infestation by houseflies. The insects are killed
at the larval stage by means of application of specified organic
carboxylic acids, especially citric acid and citrate salts, to the manure
of domesticated animals, to fixed and mobile storage containers, and to
garbage and refuse dumps or to any accidental or organic material storage
site where insect larvae may be harbored.
The active compounds are C.sub.2 to C.sub.6 aliphatic carboxylic acids and
their salts, excluding acetic acid and the salts of acetic acid.
The active compounds may be formulated with conventional insecticide
adjuvants and vehicles and may be applied as dry powders, as granules, as
aerosols, aqueous solutions, or solutions in organic solvents.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention is a method and formulations for control of insects which
have a site of habitation in food storage sites, manure, garbage, trash,
soil, or sanitary landfills. The term "insect" includes a member of the
class Insecta as well as spiders, mites, ticks, centipedes, and similar
members of the phylum Arthropoda. Insects are susceptible to destruction
by treatment with organic carboxylic acids while at the larval stage of
development. Insects of the order Diptera are most susceptible. The most
preferred target insects are those of the family Muscidae, which include
the housefly, face fly, and stable fly, among others.
Sites of habitation which may be treated with the larvacide include food
and agricultural product storage sites, domesticated animal barns, poultry
farm buildings, garbage and trash dumps, fixed and mobile storage
containers for garbage or refuse in homes and industry, sanitary
landfills, or any other sites, including accidental sites, where insect
larvae may be harbored.
The claimed compounds are C.sub.2 to C.sub.6 saturated and unsaturated
aliphatic carboxylic acids that contain between 1 and 4 carboxylic acid
(--COOH) groups, 0 to 5 hydroxyl (alcohol) groups, 0 to 3 carbonyl
(.dbd.C.dbd.O) groups, 0 to 2 carbon-carbon double bonds, and 0 to 1
carbon-carbon triple bonds and their salts excluding acetic acid and salts
of acetic acid. Salts include but are not limited to Na.sup.+, K.sup.+,
Ca.sup.++, Li.sup.+, Mg.sup.++, NH.sub.4.sup.+, primary, secondary,
tertiary, or quaternary ammonium, salts of the compounds. The term
"compound" in this disclosure means the above carboxylic acids and their
salts. The compounds include common organic acids such as citric acid,
lactic acid, propionic acid, maleic acid, tartaric acid, gluconic acid,
fumaric acid, adipic acid, sorbic acid, malonic acid, malic acid, and
their salts. All stereoisomers of the above carboxylic acids and salts
having chiral centers are active as larvacides, as are those carboxylic
acids and salts cited above which do not have optically active centers.
Mixtures of two or more of the carboxylic acids may be used; likewise
mixtures of acids and their respective salts, or mixtures of one or more
acids and one or more salts may be used.
Salts of acetic acid are not effective as larvacides.
Formic acid and salts of formic acid probably are effective larvacides but
are not suitable for this use because of the animal toxicity of these
compounds.
The exact mode of action of the above compounds is unknown. Without wishing
to be bound by this discussion of the mode of action, we believe activity
may be attributed to one or more of the following factors: 1. A decrease
in the pH of the material adjacent to the larvae, which causes a
deleterious effect on the larvae, 2. An increase in the osmotic potential
in the material adjacent to the larvae, causing dehydration, 3. The
disruption of the citric acid cycle within the larvae, perhaps with some
other unknown mechanism. It is possible that, in addition to controlling
the larval stage, the compounds may effect some control over the adult
stage insects.
The compounds preferentially are applied to the treated environments at a
rate of 1 to 100 grams of active compound per square foot of treatment
area. This range of application rates is approximately equivalent to 0.4%
to 40% by weight of active compound to manure. Typically applications are
made one to three times per week. In certain circumstances applications
may be made as infrequently as once a month or as frequently as 12 times
per day. The active compounds and formulations should be applied in the
absence of high wind and should not be sprayed directly onto animals which
might inhale the spray.
The compounds may be formulated with adjuvants and vehicles such as water
or organic solvents as are other insecticides. Dyes, such as methylene
blue, may be included in the formulation at concentrations from 0.1 to
2.0% by weight of active compound in order to aid in the even application
of the larvacide formulation. Surfactants, such as sodium lauryl sulfate,
may be included at concentrations from 0.1 to 5.0% by weight of compound
to aid in the penetration or distribution of liquid formulations. Liquid
formulations may be made in various vehicles, such as water or organic
solvents. A drift reducing agent, such as carboxymethylcellulose or
starch, may be included at concentrations from 0.1 to 5.0% by weight of
active compound in order to aid in the application of liquid larvacide
formulations by reduction of misting. Buffering agents, such as sodium or
potassium salts of phosphoric acid, may be included at concentrations from
0.1 to 50% by weight of compound to provide a desirable pH for the
formulation. Fragrances, such as peppermint oil, may be included at
concentrations from 0.1 to 2.0% by weight compound to counter the odor of
sites of habitation to be treated.
A preferred larvacide formulation may be prepared as follows:
______________________________________
Ingredient Grams
______________________________________
Sodium propionate 400
Methylene blue 4
Sodium lauryl sulfate
4
Peppermint oil 6
Water 600
______________________________________
Such a formulation is applied by spraying or as an aerosol.
The claimed active compounds and formulations of them may be applied dry or
as aqueous solutions or as organic solvent solutions. Suitable organic
solvents include methanol, ethanol, and dimethylsulfoxide. Solutions may
be sprayed using hand-held or back-pack sprayers. Alternatively, solutions
may be sprayed using a fixed, automatically-timed spray system. Solids may
be applied by dusting, by spreading as granules, or as an aerosol.
EXAMPLE 1
Citric Acid and Sodium Citrate Control of Houseflies
Aqueous solutions of citric acid and sodium citrate were each applied to a
souffle cup containing 100 grams of fresh poultry manure at the rate of 0,
4, and 8% w/w (active compound/manure). Each cup was seeded with 25
one-day old housefly larvae. After 10 days pupae were extracted and
counted.
______________________________________
Treatment* Percent Control
______________________________________
Check 10
Citric Acid (4% w/w)
100
Citric Acid (8% w/w)
100
Sodium Citrate (4% w/w)
62
Sodium Citrate (8% w/w)
100
______________________________________
*Rates of active compounds (applied as 40% aqueous solution) calculated a
percentage of manure weight.
This showed that citric acid and sodium citrate were active in preventing
the pupation, and thereby preventing the maturation, of housefly larvae.
EXAMPLE 2
Citric Acid and Control of Houseflies in a Chicken Pen 1
Ten white leghorn chickens were housed in cages contained within each of
two side-by-side, 7.times.2.3 meter, screened pens. Chicken manure was
allowed to accumulate under the cages on a concrete floor for several
days, after which time the pens were completely cleaned out and the
experiment started. Starting two days after the pens were cleaned out,
citric acid (40% w/w aqueous solution) was applied directly to the newly
accumulated chicken manure on the concrete floor under one pen. The citric
acid was applied using a hand sprayer at the rate of 8% w/w citric acid to
freshly accumulated manure or about 18 grams citric acid per square foot
of manure surface. Applications were continued every other day for 14 days
for a total of 8 applications. The check pen received equivalent
applications of water.
On the tenth day, approximately 2000 adult houseflies (Musca domestica)
were released into each pen. Fly numbers in each pen were determined by
trapping with a Tiger Farm Box Trap starting 1 week after the last
application. After 6 weeks of trapping, total flies caught were 75 times
higher in the check pen than in the treated pen effecting a control rate
of 98.7 percent.
______________________________________
Number of Adult Houseflies Caught
Days After Last Treatment
Treated* Untreated
______________________________________
39 12 182
48 0 6229
53 114 3046
Total 126 9457
______________________________________
*Application of citric acid at 8% w/w citric acid to fresh manure as a 40
w/w aqueous solution made every other day for 14 days.
This showed that treatment of chicken manure with citric acid followed by
exposure to houseflies greatly inhibited the subsequent infestation of the
manure by houseflies.
EXAMPLE 3
Citric Acid and Control of Houseflies in a Chicken Pen 2
Twenty white leghorn chickens were housed in cages contained within each of
two side-by-side, 7.times.2.3 meter, screened pens. Chicken manure was
allowed to accumulate under the cages on a concrete floor for several
days, after which time the floors of the pens were completely cleaned.
Starting two days after the pens were cleaned, citric acid (40% w/w
aqueous solution) was applied to the freshly accumulating manure in one
pen with a hand sprayer at the rate of 8% w/w of the freshly accumulated
manure, or 18 grams per square foot of manure surface. Applications were
continued every other day for 20 days, for a total of 11 applications. The
check pen received equal applications of water only.
On the twelfth day, approximately 2000 adult houseflies (Musca domestica)
were released into each pen. Fly numbers in each pen were determined by
trapping with a Tiger Farm Box Trap. After 3 weeks of trapping, total
flies caught were 22 times higher in the check pen than in the treated
pen.
______________________________________
Number of Adult Houseflies Caught
Days After Last Treatment
Treated* Untreated
______________________________________
13 294 7308
20 513 1019
27 450 10698
Total 1257 28197
______________________________________
*Application of citric acid at 8% w/w citric acid to fresh manure as a
40%, w/w aqueous solution made every other day for 20 days.
This showed that treatment of chicken manure with citric acid followed by
exposure to houseflies greatly inhibited the subsequent infestation of the
manure by houseflies.
EXAMPLE 4
Compounds and Prevention of Housefly Pupation
Aqueous solutions of citric acid, lactic acid, gluconic acid, sodium
adipate, calcium propionate, and sodium acetate were each applied to
respective containers holding 384 grams of fresh poultry manure at the
rate of 4% w/w (anion of compound/manure). Each container was seeded with
25 one day old housefly larvae. After ten days pupae were extracted and
counted.
______________________________________
Treatment Percent Control*
______________________________________
Citric Acid 85
Lactic Acid 85
Gluconic Acid 100
Sodium Adipate 100
Calcium propionate
55
Sodium Acetate 0
______________________________________
*Calculated using Abbott's Formula for check having 400 grams manure and
no added compound.
This shows the activity of citric acid, lactic acid, gluconic acid, sodium
adipate, calcium propionate, in preventing housefly pupation. Sodium
acetate was inactive in preventing housefly pupation.
It will be apparent to those skilled in the art that the examples and
embodiments described herein are by way of illustration and not of
limitation, and that other examples may be used without departing from the
spirit and scope of the present invention, as set forth in the appended
claims.
Top